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Wednesday, May 11, 2016

Stand Back From The Edge...

A young couple were walking along a country path near a seaside in England. The path ran along a tall bluff, overlooking a brilliant sea. The drop from the edge to the rocky shore and water below was over a thousand feet straight down. The weather was postcard perfect; blue skies, cool temperatures, and the still of an English morning. The young lovers wanted to get closer to the edge, but a fence had been erected by local authorities to prevent this.

People with local knowledge knew things about this precipice that strangers - new people - did not. That was why the fence had been erected.

"Hey look!" one of the pair said. "The fence ends up there, just another hundred yards!" "Let's go up there!"

They walked to the end of the barricade and turned toward the edge of the cliff. Underfoot, grasses and loose gravel made walking tricky, but the lure of the edge pulled them forward. As they got closer, within a few yards, the more cautious of the two said,

"Hey baby. Be careful. Not too close."

"It's okay," the other replied. "I know what I am doing!" They tiptoed to the edge, and even leaned over it slightly. The view was breathtaking, and made them dizzy. It was exciting! The cautious one pulled her head back and said, "that's enough!"

They returned home.

Five years passed...

To celebrate their anniversary, they returned to the same village, stayed in the same inn, and walked the same path. This time though, the skies were grey, and the wind blustered and spit the spray carried up the cliff and over the edge. They were determined not to let the gale dampen their spirits, and they walked along hand in hand, with slickers to protect them from the wet.

The wind was fitful, and contrary. It blew first this way, then that. It varied in intensity, and occasionally blew a gust that lifted their jackets.

Again they came to the edge of the fence, put there to protect them. Again the bold one said, "let's go look! We did it before, we can to do it again!" Worry was apparent in the other lover's reply, "I don't know. It's different now. Maybe we shouldn't."

"Come on...It will be okay! I know what I am doing!"

They crept up near the edge, the wind making it difficult to keep their balance. The cautious one crouched and sat down. "You chicken!" said the other. "We've done this before!"

At that instant, a surge of wind rising up the vertical wall formed a vortex above the edge. With startling speed and force the wind direction shifted from onshore to off, The young lover - still standing - was blown toward the edge.

Too late! - realization. Too close to the edge of ability! Too unpredictable the wind!

SOUTH ST. LOUIS, MO (KTVI) – The investigation into the Friday night crash of an ARCH Medi-Vac helicopter could take as long as one year. The helicopter was heading to the Saint Louis University Hospital helipad around 11:00pm when it failed to achieve enough altitude to land. Its rotors struck the side of an outpatient clinic building before it crashed on the parking lot below.

From the NTSB...

On March 6, 2015, at 2310 central standard time, an Airbus Helicopters (Eurocopter) EC-130-B4, N356AM ... struck the edge of a hospital building and impacted its parking lot during a visual approach to the St Louis University Hospital elevated rooftop helipad (MO55), St Louis, Missouri. During the approach, the helicopter experienced a loss of directional control and entered an uncontrolled descent. The helicopter was destroyed by impact forces and a post-crash fire. The commercial pilot, who was the sole occupant, sustained fatal injuries. The helicopter was operated under Title 14 CFR Part 91 as an air medical positioning flight that was operating on a company flight plan. Night visual meteorological conditions prevailed at the time of the accident. The flight was returning to MO55 after it had been refueled at the operator's base in St. Louis, Missouri.

The flight's first approach and landing at MO55 was to drop off a medic, nurse, and a patient. During the approach, the pilot reported to the flight nurse and medic that winds were gusting to 25 knots. The flight nurse stated that helicopter was yawing quite a bit and there was a noticeable roll side to side during landing. The helicopter landed without incident during the first approach and landing. The flight then departed to obtain fuel at the operator's base and then departed to return to MO55, to pick up the medic and flight nurse.

The accident occurred during the return's approach for landing at MO55.

The medevac helicopter lifted off the hospital's roof-top helipad at night. The pilot made a right pedal turn to the northwest, facing a building that extended above the height of the helipad by approximately 10-feet. The paramedic said that when the helicopter was about 20-feet above the helipad, and while he was programming the GPS receiver, a "sudden gust" of wind push the helicopter from directly behind. He was not alerted to anything unusual until he looked up and noticed the helicopter's close proximity to a 16-floor brick building, located at the northern corner of the heliport, which extended above the height of the helipad by 4 floors. The paramedic yelled, "building, building, building!" to alert the pilot. The pilot then made a rapid right cyclic input to avoid hitting the building, but the helicopter struck the building, and fell about 13 floors to ground level.

On April 15, 2016, about 1955 eastern daylight time, a Eurocopter France AS350B2, N561AM, was substantially damaged after it impacted terrain near Jasper, Georgia. The commercial pilot and three medical flight crewmembers were not injured. Visual meteorological conditions prevailed. The helicopter was operating on a company visual flight rules flight plan from Lanier Park Hospital Heliport (38GA), Gainesville, Georgia, to a helipad at Piedmont Mountainside Hospital, Jasper, Georgia. The helicopter emergency medical service flight was conducted under the provisions of 14 Code of Federal Regulations Part 135.

According to the pilot, he made a downwind approach to the helipad over high tension power lines and then turned onto the final leg of the approach. Then, he noted that the tail rotor became "difficult to control" and the helicopter began a "rapid descent with forward airspeed." The pilot reduced the power and unsuccessfully attempted to perform a go-around maneuver. He configured the helicopter for landing by maintaining forward airspeed, raised the nose of the helicopter, however it impacted the ground and "bounced" three times prior to coming to rest. The pilot and three medical crew members then exited the helicopter without anomaly.

A post-accident examination of the helicopter revealed that the tail-boom had partially separated from the airframe, which resulted in substantial damage. In addition, there were no anomalies noted with the airframe or engine that would have precluded normal operation prior to the accident.

Does anyone see a pattern here? Please forgive my sorry attempt at allegory. I am trying to sound the alarm without sounding "alarmist." I don't want to imply that helicopters can't safely land and takeoff from pinnacles and confined areas (hospital helipads), but I think we as an industry aren't doing enough to prepare ourselves for the environments we will have to face as we conduct these operations. I understand that vested interests want to downplay the dangers of flying in a helicopter.

Talking about crashes is bad for business. But it is the best way we know to prevent more crashes...

Some ground-based hospital helipads are one-way tree-traps. Hospital administrators apparently ask the groundskeeper or the landscape designer where to put the cement. Some roof-top pads are surrounded by higher buildings that can funnel and shape wind into a hazardous air-hammer that acts on a helicopter like a Hollywood special-effect. Only experiencing them isn't special - it's terrifying. If you live through it, one time is all it takes to know better next time. That's what happens to most of us. We creep up to the edge of the precipice, to the edge of aircraft controllability, to the edge of hurting ourselves. And then we know. But what about the others who don't yet know. Should we let them find out for themselves in some sort of Darwinian thinning of the flock?

We need to be talking about this. But the operators don't. At least not any of the four I have worked for. They all left this up to a pilot's experience. Or "tribal knowledge" (whatever the hell that is). Mind you, a HEMS pilot used to come to the game with 3000 hours of flight experience, often in combat, often in a variety of environments, often with actual IMC flying experience.

Those days are over. Here's today's pipeline; civil instruction, instructing, an IFR ticket with no cloud time. Time building offshore, and then welcome to HEMS.... Pilots receive a minimum of environmental training, unless it's required for a specific job, like long-line. Today's requirements for a HEMS job are more relaxed than they were when I started in 1999, in both quantity and quality. Employers are dipping deeper into the labor pool. It shows.

An anecdote. Yesterday, May 10th 2016, I asked a flight nurse at a random base in the US to ask the pilot, on duty with him a question.

"What is the maximum downwind component with which you can land at a hospital helipad?" The answer? "Seventeen knots." So where does that number come from? Seventeen knots happened to be the windspeed at the airport on the day of that aircraft's certification testing for controllability in a crosswind.

The test-pilot, flying over a flat, unobstructed airport, wanted to show that the helicopter was capable of flying in adverse conditions, like a crosswind. This helps sell helicopters. The test pilot was able to control the helicopter that day, in that environment, and the measured windspeed was 17 knots. So the certifying body allowed the manufacturer to put that number in the rotorcraft flight manual.

What does 17 knots mean to us as we head into a hospital helipad with a tail wind? Not one darned thing. And the pilot who was asked that question hasn't been taught that by the people who hired him, and trained him, and put him on the line flying HEMS. So as it stands today, he will learn about landing at a hospital helipad with a crosswind or tailwind by trial and error. And he will probably be okay.

Probably...

That question, asked of a random HEMS pilot, was my non-scientific research into the need for this blogpost. I actually need to be studying for the USCG captain's test right this minute, but my conscience is driving me to sit here and write this. I don't want to read about any more crashes or meet any more widows. I mean, really, haven't we had enough of that? If the operators won't fix this mess we will have to fix it ourselves. "Okay Maverick, it's time for some of that pilot stuff."

I ask you pilots who have been at this awhile to help your brothers and sisters out. Talk about this at shift change. Talk about the scary helipads in your area. Talk about the conditions you will tolerate, and those you won't. Share some of that "tribal knowledge." If you want to be really squared away come up with a locally produced task-condition-standard for cross-wind, tail-wind, high-wind, and gust-spread landings at any confined or obstructed pinnacle helipads in your area.

Don't bet your life on the head-shed handling this...

Finally - if it was me - having to land downwind in a heavily-loaded helicopter into a confined area or onto a pinnacle affected by other taller structures? The maximum tail-wind or crosswind component would be 5 knots or less. Not 17 knots. With no, zero, nada, zilch, gust-spread. If I can't land into a stable flowing wind while going into a crappy obstructed confined hell-hole, I am going somewhere else. Winds gusting around obstacles create shear, instant changes in lift and drag that affect different portions of the rotor disk differently, coupled with instant changes in tail rotor authority. Aircraft control can be here one instant, gone the next. I am going somewhere else. Like to an airport. The kind of place where that 17 knot number came from.

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About Me

I am a retired army aviator, and flew EMS helicopters from 1999 until 2015. I have flown at many different programs under traditional, community based, and hybrid models. I enjoy interacting with crewmembers as we together learn how to avoid becoming a statistic and the topic of someone else's safety brief. I teach Air Medical Resource Management, and am a member of the National EMS Pilot's Association's board of directors.